Method of and apparatus for producing steroscopic pictures



y 9- c. F. MENDEZ 2,157,138

METHQD OF AND APPARATUS FOR PRODUCING STEREOSCOPIC PICTURES Filed July8, 1936 2 Sheets-Sheet l gay/@424 C. F. MENDEZ May 9, 1939.

METHOD OF AND APPARATUS FOR PRODUCING STEREOSCOPIC PICTURES 2Sheets-Sheet 2 Filed July 8, 1936 Ji l mm @mm d JI d Patented May 9,1939 UNITED STATES PATENT OFFICE METHOD OF AND APPARATUS FOR PRO- DUCINGSTEREOSCOPIC PICTURES 2 Claims.

My invention consists of a new and useful improvement in Method of andapparatus for producing stereoscopic pictures and is an improvement uponmy invention described and claimed in my co-pending application forUnited States .Letters Patent, Serial Number 69,195, filed March 16,1936. In my aforesaid invention, the stereoscopic effect is procured bythe use of a concave reflecting surface generated by a line moving in anarcuate path disposed in a substantially horizontal plane. Such asurface produces a degree of objectionable distortion, and it is tocorrect such distortion that my present invention is designed.Essentially, my invention consists in producing stereoscopic pictures bythe use of a concave reflecting surface causing horizontal distortion,and vertically distorting the images, either before or after theirhorizontal distortion, to compensate for the necessary horizontaldistortion, and thereby produce symmetrical images. As hereinafter fullydescribed, the result can be accomplished in a variety of ways, Thepictures may be initially vertically distorted, either by photographingwith a proper form of lens, in reproducing the prints or films with sucha lens, or by projection with such a lens. When such verticallydistorted pictures are reflected from the concave surface the observedpictures will be symmetrical.

My invention also makes possible the horizontal increase of theeifectiveprotographic field of a standard photographic film, since thepictures may be vertically distorted, as above mentioned in thephotographing, permitting a greater photographic area to be placedwithin the limits of the film, and subsequently horizontally distorted,to restore symmetry.

While I have illustrated in the drawings filed herewith and havehereinafter fully described several embodiments of my invention, it isto be distinctly understood that I do not consider my invention limitedto said specific embodiments, but refer for its scope to the calmsappended hereto.

In the drawings:

Fig. 1 is a diagrammatic illustration of that form of my invention inwhich the proper form of lens is used in the projection of the pictures,to distort the initial images vertically.

Fig. 2 is a diagrammatic illustration of that form of my invention inwhich the vertical distortion of the images is secured in the originalpicture by the use of the proper form of lens either in photographic orprinting the picture.

Fig. 3 is a diagrammatic illustration of a portion of a standard motionpicture film.

Fig. 4 is a diagrammatic illustration of the initial step in that formof my invention in which the effective photographic field ishorizontally in-. creased, showing the vertical distortion of images inthe field, by the use of the proper form of lens.

Fig. 5 is a diagrammatic illustration of the second step showing thecorresponding horizontal distortion of the images reflected from theconcave surface, thereby restoring symmetry.

Fig. 6 is a diagrammatic illustration of the image projected upon theobserved surface, by theusual method of projection of a standard filmsuch as is illustrated in Fig. 3.

Fig. '7 is a diagrammatic illustration of the images projected upon theobserved surface, by the use of my invention illustrated in Figs. 4 and5.

As illustrated in Fig.1, the image I shown as a circle having thehorizontal and vertical diameters la and lb is projected through thelens 2 upon the translucent screen 3. By reason of the character of thelens 2, the image 4 caused to appear upon the screen 3 is distortedvertically, its horizontal diameter 4a being the same as the horizontaldiameter la, but its vertical diameter 4b being greater than thevertical diameter lb. The reflecting surface 5, because of thecharacterof its surface causing horizontal distortion, reflecting the image 4produces the image 6 having the horizontal diameter 6a greater than thehorizontal diameter 4a and the vertical diameter 617 the same as thevertical diameter 4b. Since the lens 2 and the reflecting surface 5 aredesigned to effect the corresponding degrees of vertical and horizontaldistortion respectively, it is obvious that the horizontal and verticaldiameters 6a and 6b of the image 6 are identical, thus producing acircle, whereby the requisite horizontal distortion of therefiectingsurface 5 has been compensated to produce a symmetrical image 6, asobserved by the eye E.

As illustrated in Fig. 2, the image I a circle having been initiallydistorted vertically in its production by the use of the proper form oflens, has the horizontal diameter Ia and the increased vertical diameterlb, and is projected upon the translucent screen 8, causing the image 9having the horizontal and verticaldiameters 9a and 9b corresponding withthe diameters la and lb. The reflecting surface 10, because of itscharacter causing horizontal distortion reflecting the image 9 producesthe image ll having the horizontal diameter Ha greater than thehorizontal diameter 9a of the image 9, and the vertical diameter H b thesame as the vertical diameter 9b. Since the initial vertical distortionof the image 1 and the horizontal distortion of the reflecting surfaceiii precisely correspond, it is obvious that the horizontal and verticaldiameters i la and l lb of the image H are identical, thus producing acircle, whereby the requisite horizontal distortion of the reflectingsurface H has been compensated to produce a symmetrical image asobserved by the eye E.

As illustrated in Fig. 3, the portion of a standard film 26 has theeffective photographic field N in which are produced the three images2&3 in the form of circles. As illustrated in Fig. 4, the portion of astandard film 29 has the effective field 30 of the same size as thefield 27. By the use of the proper character of lens 3!! producingvertical distortion, the six objects 32 are delineated in the field 29as the vertically distorted images 33. As illustrated in Fig. 5, theimages 33, each having the horizontal diameter 33a and the increasedvertical diameter 331), are projected upon the translucent screen 341causing the images 35, each having the horizontal and vertical diameters35a and 351) corresponding with the diameters 33a and 33b. The concavecylindrical reflecting surface 36 having a vertical axis, generated by astraight vertical line moving in an arcuate path disposed in ahorizontal plane, with the chord of the arc of said surface at an angleto the plane of said screen, because of its character causing horizontaldistortion, reflecting the images 35 produces the images 37, each havingthe horizontal diameter 371a greater than the horizontal diameter 35a ofeach of the images 35, and the vertical diameter 31b the same as thevertical diameter 35b. Since the lens 3i and the reflecting surface 36are designed to effect the corresponding degrees of vertical andhorizontal distortion respectively, it is obvious that the horizontaland vertical diameters 371a and 312; are identical, thus producingcircles, as observed by the eye E.

As illustrated in Fig. 6, there are projected by the usual method on thescreen 38 the three images 39 from the images 28 of the film 26. As

illustrated in Fig. 7, there can be projected upon the surface 36, thesix images 31 from the images 33 of the film 29. Thus it is obvious thatby the use of my improved method, the field has been horizontallyincreased to project the images of not three objects but six, by the useof the same size film field, on a horizontally increased observedsurface.

Having described my invention, what I claim is:

1. The method of producing stereoscopic pictures which comprisesphotographing objects,

' laterally increasing the photographic field by vertically distortingthe picture to a determined deree; projecting the vertically distortedreal picture upon a plane screen; and reflecting the said picture from aconcave, cylindrical surface, placed, adjusted and disposed to produce ahorizontally distorted virtual'image to compensate the distortion of thephotographic field, which surface by laterally and uniformly deviatingthe reflected light rays produces the required degree of horizontalparallax uniformly throughout the Whole picture, to provide forobservers at different lateral selected places laterally and parallellydisplaced images, so that the binocular vi- 7 determined degree; avertically disposed plane screen; means to project aipon said screen thevertically distorted real pictures; means to compensate the saiddistortion and to secure the necessary uniform degree of horizontalparallax through the whole picture, comprising a concave, cylindricalreflecting surface, having a vertical axis, generated by a straightvertical line moving in an ar'cuate path disposed in a horizontal plane,with the chord of the arc of said surface at an acute angle to the planeof said screen, to cause the said reflecting surface to reflect thepictures to observers, distort horizontally the images thereof, andlaterally and uniformly deviate their light rays to produce a lateralparallel displacement of the said images from difierent lateral pointsof view, the arc of curvature of the reflector being uniform throughoutits entire height, and being adjusted wtih reference to the distancebetween the plane of the screen and the reflecting surface tosymmetrically compensate the said'vertical distortion, restore thelength of the lateral visual field and provide identical images in thatprecise degree of lateral parallel displacement as to be perceivedbinocularly from selected places of observation as a single undistortedimage having, throughout, the right distances of depth which existedbetween the objects when originally photographed.

CIRO FIDEL MENDEZ.

